diff options
Diffstat (limited to 'target/linux/s3c24xx/patches-2.6.24/1214-introduce-resume-exception-capture.patch.patch')
| -rw-r--r-- | target/linux/s3c24xx/patches-2.6.24/1214-introduce-resume-exception-capture.patch.patch | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/target/linux/s3c24xx/patches-2.6.24/1214-introduce-resume-exception-capture.patch.patch b/target/linux/s3c24xx/patches-2.6.24/1214-introduce-resume-exception-capture.patch.patch new file mode 100644 index 0000000000..e5900e0233 --- /dev/null +++ b/target/linux/s3c24xx/patches-2.6.24/1214-introduce-resume-exception-capture.patch.patch @@ -0,0 +1,264 @@ +From 8e18a9db5f895f654b06000d7bd10528e6b795f3 Mon Sep 17 00:00:00 2001 +From: Andy Green <andy@openmoko.com> +Date: Wed, 2 Jul 2008 22:44:11 +0100 +Subject: [PATCH] introduce-resume-exception-capture.patch + +This patch introduces a new resume debugging concept: if we +get an OOPS inbetween starting suspend and finishing resume, it +uses a new "emergency spew" device similar to BUT NOT REQUIRING +CONFIG_DEBUG_LL to dump the syslog buffer and then the OOPS +on the debug device defined by the existing CONFIG_DEBUG_S3C_UART +index. But neither CONFIG_DEBUG_LL nor the S3C low level configs +are needed to use this feature. + +Another difference between this feature and CONFIG_DEBUG_LL is that +it does not affect resume timing, ordering or UART traffic UNLESS +there is an OOPS during resume. + +The patch adds three global exports, one to say if we are inside +suspend / resume, and two callbacks for printk() to use to init +and dump the emergency data. The callbacks are set in s3c serial +device init, but the whole structure is arch independent. + +Signed-off-by: Andy Green <andy@openmoko.com> +--- + drivers/serial/s3c2410.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++ + include/linux/kernel.h | 2 + + include/linux/suspend.h | 6 ++++ + kernel/power/main.c | 10 ++++++- + kernel/printk.c | 41 +++++++++++++++++++++++++++ + 5 files changed, 127 insertions(+), 1 deletions(-) + +diff --git a/drivers/serial/s3c2410.c b/drivers/serial/s3c2410.c +index 73c6284..fef3c8f 100644 +--- a/drivers/serial/s3c2410.c ++++ b/drivers/serial/s3c2410.c +@@ -81,6 +81,7 @@ + + #include <asm/plat-s3c/regs-serial.h> + #include <asm/arch/regs-gpio.h> ++#include <asm/arch/regs-clock.h> + + /* structures */ + +@@ -992,6 +993,69 @@ static struct s3c24xx_uart_port s3c24xx_serial_ports[NR_PORTS] = { + #endif + }; + ++static void s3c24xx_serial_force_debug_port_up(void) ++{ ++ struct s3c24xx_uart_port *ourport = &s3c24xx_serial_ports[ ++ CONFIG_DEBUG_S3C_UART]; ++ struct s3c24xx_uart_clksrc *clksrc = NULL; ++ struct clk *clk = NULL; ++ unsigned long tmp; ++ ++ s3c24xx_serial_getclk(&ourport->port, &clksrc, &clk, 115200); ++ ++ tmp = __raw_readl(S3C2410_CLKCON); ++ ++ /* re-start uart clocks */ ++ tmp |= S3C2410_CLKCON_UART0; ++ tmp |= S3C2410_CLKCON_UART1; ++ tmp |= S3C2410_CLKCON_UART2; ++ ++ __raw_writel(tmp, S3C2410_CLKCON); ++ udelay(10); ++ ++ s3c24xx_serial_setsource(&ourport->port, clksrc); ++ ++ if (ourport->baudclk != NULL && !IS_ERR(ourport->baudclk)) { ++ clk_disable(ourport->baudclk); ++ ourport->baudclk = NULL; ++ } ++ ++ clk_enable(clk); ++ ++ ourport->clksrc = clksrc; ++ ourport->baudclk = clk; ++} ++ ++static void s3c2410_printascii(const char *sz) ++{ ++ struct s3c24xx_uart_port *ourport = &s3c24xx_serial_ports[ ++ CONFIG_DEBUG_S3C_UART]; ++ struct uart_port *port = &ourport->port; ++ ++ /* 8 N 1 */ ++ wr_regl(port, S3C2410_ULCON, (rd_regl(port, S3C2410_ULCON)) | 3); ++ /* polling mode */ ++ wr_regl(port, S3C2410_UCON, (rd_regl(port, S3C2410_UCON) & ~0xc0f) | 5); ++ /* disable FIFO */ ++ wr_regl(port, S3C2410_UFCON, (rd_regl(port, S3C2410_UFCON) & ~0x01)); ++ /* fix baud rate */ ++ wr_regl(port, S3C2410_UBRDIV, 26); ++ ++ while (*sz) { ++ int timeout = 10000000; ++ ++ /* spin on it being busy */ ++ while ((!(rd_regl(port, S3C2410_UTRSTAT) & 2)) && timeout--) ++ ; ++ ++ /* transmit register */ ++ wr_regl(port, S3C2410_UTXH, *sz); ++ ++ sz++; ++ } ++} ++ ++ + /* s3c24xx_serial_resetport + * + * wrapper to call the specific reset for this port (reset the fifos +@@ -1167,6 +1231,11 @@ static int s3c24xx_serial_resume(struct platform_device *dev) + static int s3c24xx_serial_init(struct platform_driver *drv, + struct s3c24xx_uart_info *info) + { ++ /* set up the emergency debug UART functions */ ++ ++ printk_emergency_debug_spew_init = s3c24xx_serial_force_debug_port_up; ++ printk_emergency_debug_spew_send_string = s3c2410_printascii; ++ + dbg("s3c24xx_serial_init(%p,%p)\n", drv, info); + return platform_driver_register(drv); + } +diff --git a/include/linux/kernel.h b/include/linux/kernel.h +index 94bc996..8e565b4 100644 +--- a/include/linux/kernel.h ++++ b/include/linux/kernel.h +@@ -182,6 +182,8 @@ asmlinkage int printk(const char * fmt, ...) + extern int log_buf_get_len(void); + extern int log_buf_read(int idx); + extern int log_buf_copy(char *dest, int idx, int len); ++extern void (*printk_emergency_debug_spew_init)(void); ++extern void (*printk_emergency_debug_spew_send_string)(const char *); + #else + static inline int vprintk(const char *s, va_list args) + __attribute__ ((format (printf, 1, 0))); +diff --git a/include/linux/suspend.h b/include/linux/suspend.h +index 4360e08..7186eef 100644 +--- a/include/linux/suspend.h ++++ b/include/linux/suspend.h +@@ -122,6 +122,12 @@ struct pbe { + struct pbe *next; + }; + ++/** ++ * global indication we are somewhere between start of suspend and end of ++ * resume, nonzero is true ++ */ ++extern int global_inside_suspend; ++ + /* mm/page_alloc.c */ + extern void drain_local_pages(void); + extern void mark_free_pages(struct zone *zone); +diff --git a/kernel/power/main.c b/kernel/power/main.c +index f71c950..d87bf0d 100644 +--- a/kernel/power/main.c ++++ b/kernel/power/main.c +@@ -31,6 +31,10 @@ DEFINE_MUTEX(pm_mutex); + unsigned int pm_flags; + EXPORT_SYMBOL(pm_flags); + ++int global_inside_suspend; ++EXPORT_SYMBOL(global_inside_suspend); ++ ++ + #ifdef CONFIG_SUSPEND + + /* This is just an arbitrary number */ +@@ -156,10 +160,12 @@ int suspend_devices_and_enter(suspend_state_t state) + if (!suspend_ops) + return -ENOSYS; + ++ global_inside_suspend = 1; ++ + if (suspend_ops->set_target) { + error = suspend_ops->set_target(state); + if (error) +- return error; ++ goto bail; + } + suspend_console(); + error = device_suspend(PMSG_SUSPEND); +@@ -183,6 +189,8 @@ int suspend_devices_and_enter(suspend_state_t state) + device_resume(); + Resume_console: + resume_console(); ++bail: ++ global_inside_suspend = 0; + return error; + } + +diff --git a/kernel/printk.c b/kernel/printk.c +index 89011bf..c8691bc 100644 +--- a/kernel/printk.c ++++ b/kernel/printk.c +@@ -33,8 +33,11 @@ + #include <linux/bootmem.h> + #include <linux/syscalls.h> + #include <linux/jiffies.h> ++#include <linux/suspend.h> + + #include <asm/uaccess.h> ++#include <asm/plat-s3c24xx/neo1973.h> ++#include <asm/arch/gta02.h> + + #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT) + +@@ -61,6 +64,12 @@ int console_printk[4] = { + int oops_in_progress; + EXPORT_SYMBOL(oops_in_progress); + ++void (*printk_emergency_debug_spew_init)(void) = NULL; ++EXPORT_SYMBOL(printk_emergency_debug_spew_init); ++ ++void (*printk_emergency_debug_spew_send_string)(const char *) = NULL; ++EXPORT_SYMBOL(printk_emergency_debug_spew_send_string); ++ + /* + * console_sem protects the console_drivers list, and also + * provides serialisation for access to the entire console +@@ -653,6 +662,38 @@ asmlinkage int vprintk(const char *fmt, va_list args) + /* Emit the output into the temporary buffer */ + printed_len = vscnprintf(printk_buf, sizeof(printk_buf), fmt, args); + ++ /* if you're debugging resume, the normal methods can change resume ++ * ordering behaviours because their debugging output is synchronous ++ * (ie, CONFIG_DEBUG_LL). If your problem is an OOPS, this code ++ * will not affect the speed and duration and ordering of resume ++ * actions, but will give you a chance to read the full undumped ++ * syslog AND the OOPS data when it happens ++ * ++ * if you support it, your debug device init can override the exported ++ * emergency_debug_spew_init and emergency_debug_spew_send_string to ++ * usually force polling or bitbanging on your debug console device ++ */ ++ if (oops_in_progress && global_inside_suspend && ++ printk_emergency_debug_spew_init && ++ printk_emergency_debug_spew_send_string) { ++ unsigned long cur_index; ++ char ch[2]; ++ ++ if (global_inside_suspend == 1) { ++ (printk_emergency_debug_spew_init)(); ++ ++ ch[1] = '\0'; ++ cur_index = con_start; ++ while (cur_index != log_end) { ++ ch[0] = LOG_BUF(cur_index); ++ (printk_emergency_debug_spew_send_string)(ch); ++ cur_index++; ++ } ++ global_inside_suspend++; /* only once */ ++ } ++ (printk_emergency_debug_spew_send_string)(printk_buf); ++ } ++ + /* + * Copy the output into log_buf. If the caller didn't provide + * appropriate log level tags, we insert them here +-- +1.5.6.5 + |